Typewriter carriage return and indexing mechanism



Sept. 1, 1959 N. D. WALTON ETAL TYPEWRITER CARRIAGE RETURN AND INDEXINGMECHANISM Filed Dec. 30, 1957 3 Sheets-Sheet l IN VENTORS NEIL D. WALTONHENRY R. KRUSPE ATTORNEY Sept. 1, 1959 N. D. WALTON ETAL 2,902,133

' TYPEWRITER' CARRIAGE RETURN AND mnzxmc MECHANISM Filed bee. so, 1957 sSheets-Sheet 2 Sept'. 1, 1959 N. D. WALTON ETIAL 2,902,133

TYPEWRITER CARRIAGE RETURN AND INDEXING MECHANISM Filed Dec. 30, 1957 3Sheets-Sheet 3 United States Patent TYPEWRITER CARRIAGE RETURN ANDHVDEXING MECHANISM Neil D. Walton and Henry R. Kruspe, Lexington, Ky.,

assignors to International Business Machines Corporation, New York, N.Y., a corporation'of- New York Application December 30, I957, SerialNo.705,978

4 Claims. (Cl.. 19766) This invention relates to typewriters, and moreparticularly to mechanisms for controlling the movement of a typewritercarriage during typing operations.

All typewriters are provided with a carriage which is movable on astationary frame to obtain a positioning of type elements. and a sheetof paper such that printing takes place on the paper at the desiredlocation. Most of the typewriters in use today have a carriage carryinga platen about which the sheet of paper is wrapped. The carriage ismoved to position the paper relative to a point at which type elementsmay be engaged selectively with the paper.

In a patent application by L. E. Palmer, Serial Number 653,806, filedApril 19, 1957, there is shown a typewriter having a carriage on which atype head ismounted. The carriage is moved to position the type head forprinting on a sheet of paper wrapped about a stationary platen.

Regardless of what form the typewriter takes, the carriage is moved at acomparatively high speed from a position where typing takes place at theend of one line to a position at the beginning of the next line. It isdesirable that the carriage be stopped without excessive shock when thebeginning of a new line is reached, and it is essential thatthe'carriage always be brought to rest in the same position so that thetyping for each line is started from the same point. As the carriage ismoved to a position for typing another line, means should operateautomatically to index the platen for positioning the sheet of paperto'receive print a desired distance below the line already typed. Theindexing; means should be associated with the carriage return mechanismin such a Way that an indexing of the platen without carriage return canbe obtained, if desired.

An object of this invention is to provide an improved mechanism formoving the carriage of a typewriter from any point in one line to aposition for typing at the beginning of another line.

Another object of this invention is to provide an improved mechanism formoving a typewriter carriage with a minimum of shock and noise from anypoint in a line to a position for typing at the beginning of the line.

Still another object is to provide an improvedplaten indexing meansassociated with ya carriage moving means in such a way that an indexingof the platen is obtained simultaneously with movement of the carriage.by the moving means, or an indexing of the platen may be obtainedwhilethe moving means is held inoperative.

Other objects of the invention will be. pointed out in the followingdescription and claims and illustrated in the accompanying drawings,which disclose, by way of example, the principle of the invention andthe best mode, which has been contemplated, ofapplying that principle.

'Inthe drawings:

Fig. 1 isa. perspective view of the improved mechanism for moving atypewriter carriage from a typing position in one line to a typingposition at the beginning of an- V other line.

Fig. 2 is an enlarged sectional view of the clutch mechanism controllingthe drive of the carriage.

Fig; 3 is an elevational view taken from the right hand sideof Fig. 1.

Fig. 4 is a perspective view of mechanism for operating the escapementpawl of Fig. 1 during letter spacing.

Referring to the drawings it will be noted that there is shown in Fig. 1a mechanism for moving a carriage 2 like the carriage in the Palmerapplication referred to above. This carriage is adapted to carry a printhead, as shown in the Palmer application, which can be engaged with asheet of paper on a platen 3 to effect printing. Since the print headand the mechanism for actuating it form no part of the presentinvention, it will not be shown or described herein.

The carriage 2 is slidably mounted on a shaft 4 so as to present thetype head for printing at any point along a line on the sheet of papercarried by the platen. Fixed to the carriage is a tape or wire 5extending about pulleys 6 and 7 to a pulley 8 to which it is attached byany suitable means. The pulleys 6 and 7 are rotatably supported by fixedshafts 1 0 and ll, respectively, and pulley 8 is fixed to a rotatableshaft 12. Another tape or wire 14 is fixed to the carriage and extendsaround pulleys 15 and 16 to a pulley 17 to which it is connected by anysuitable means. Pulley 15' is rotatably supported by a stationary shaft19 while pulley 16 is rotatably supported by the shaft 11 and pulley 17is fixed to the rotatable shaft 12. The arrangement is such that arotation of the shaft 12 in a clockwise direction causes the tape 5 tobe wound onto the pulley 8 and effect movement of the carriage to theleft. During this time, the tape 14 is unwound from the pulley 17. Whenthe shaft 12 is rotated in a counterclockwise direction, the tape 14 iswound onto the pulley 17 to cause movement of the carriage to the right.

For rotating the shaft 12 in a clockwise direction, there is provided atoothed belt 20v driven at a constant speed by a power means, not shown.The belt 20 engages a toothe Whe 1'21, g. fi ed o a h f 2- E di fromtllQ'Wheel is a hub 23 which is carried by a bearing 24 mounted withinan opening in a frame plate 25. Freely mounted on the shaft 22 adjacentthe hub 23 is a sleeve shaped member 26 having an outside diameter atits left end equal to the outside diameter of a reduced portion 28 onthe hub. Surrounding the reduced portion 28 and an adjacent portion ofthe sleeve member is a coiled spring 30 which is wound in a clockwisedirection looking from left to right in Fig. 2. Fixed to the hub 23 by ascrew 31 is a bracket having a finger portion 32 extending over thespring 30 parallel to the shaft 22, and another finger portion 34 actingagainst the left hand end of the spring 30 to clamp it to the hub. Thespring 30 is wound so as to have frictional contact with the surface ofthe sleeve member 26, and the right hand end of the spring 30 is pulledby a spring 36 in a direction to in crease its frictional engagementwith the sleeve member.

Freely mounted upon the shaft 22 adjacent the sleeve member 26 is abevel gear 38 having a hub portion 39 slightly smaller in outsidediameter than a reduced portion 40 on the sleeve member. Surrounding thereduced portion 40 and part of the hub 39' is a clutch spring 41 whichis wound in a direction opposite to the direction of rotation of theshaft 22. A clamp 42 holds the left hand end of the spring for rotationwith the sleeve member 26, and a slight clearance between the spring andthe hub 39 permits the gear 38 to rotate normally free of the shaft 22and the member 26. Arranged adjacent the right end of the spring 41 is aroller 44 which may be moved by mechanism to be described later, againstthe spring 41 for forcing it into engagement with the hub .of the gear38. The friction between the hub and the spring causes the latter towind tightly against the hub and effect a driving of the gear 38.

Fixed to the shaft 12 is a bevel gear 46 meshing with the bevel gear 38.When the gear 38 is driven by engagement of the spring 41 with its hub,the shaft 12 is also driven in a clockwise direction. Surrounding theshaft 12, as shown in Fig. 2, is a helically wound spring 47 which isconnected at one end to the shaft and is connected at its other end to astationary part of the typewriter frame. This spring is wound in such adirection that it tends to rotate the shaft 12 in a counter-clockwisedirection. Fixed to the shaft 12 is a ratchet wheel 48 which is normallyengaged by a pawl 49 for holding the shaft against rotation by thespring 47. This pawl is pivotally supported by a pin 50 and is urged bya spring 51 into engagement with the ratchet wheel. Engaging a slot 53in an upwardly projecting arm of the pawl is a link 54 which isconnected to a bellcrank 55 pivotally supported on a rod 56.

The roller 44 controlling the clutch spring 41 is carried by an arm 58pivotally supported at 59 and urged by a spring 60 in a direction todisengage the roller from the clutch spring. A bellcrank 61 is operableto actuate the arm 58 for engaging the roller 44 with the clutch spring41, and a link 62 connects the bellcrank 61 to a bellcrank 63 pivotallysupported on the rod 56. The bellcranks 55 and 63 are provided with armportions 65 and 66 extending parallel to each other, and formed integralwith the arm portion 66 is a bridge portion 67 extending over the armportion 65 and having a projecting portion 68 engageable at its upperedge by a latch 70. Arranged adjacent the ends of the arm portions 65and 66 are latches 71 and 72 pivotally supported on a shaft 73 and urgedtoward each other by a spring 74. When the bellcranks 55 and 63 are inthe positions shown in Fig. 1, the pawl 49 is permitted to engage theratchet wheel 48 while the roller 44 is held out of engagement with theclutch spring 41, and the arm portions 65, 66 of the bellcranks areraised so that their upper edges are above the latches 71 and 72.Pivotally mounted on the end of shaft 73, as shown in Figs. 1 and 3, isa member 75 carrying an eccentric 76 which acts against the left edge ofthe latch 71. Projecting from this member, as shown in Fig. 3, is afinger 77 in a position to engage the right edge of the latch 72 whenthe member 75 is rocked in a counter clockwise direction. The member 75is normally rocked by a spring 79 in a clockwise direction about theshaft 73, engaging the eccentric with the latch 71 and forcing thelatter away from the arm portion 65 of the bellcrank 55. Spring 74connecting the latches operates at this time to hold the latch 72against the side of the arm portion 66 on the bellcrank 63. As shown inFig. 3, a slight clearance exists between the latch 72 and the finger 77on the member 75.

The latch 70 is pivotally connected at its lower end to a cam lever 81,and is urged by a spring 82 in a direction to engage the projectingportion 68 on the bellcrank 63. Formed upon the forward end of the camlever is a projecting portion 84 carrying a cam 85 which is adapted torotate into engagement with a power roll 86 fixed to the rotating shaft22. A spring actuated arm 87 acts against a stud 88 on the cam forurging the latter in a clockwise direction to engage the power roll. Atthe opposite side of the cam is a stud 90, see Fig. 3, normally engaginga latch 91 which holds the cam free of the power roll. The latch 91 isurged by a spring 92 about a pivot point 93 on the cam lever to aposition in which the end of the latch lies in the path of the stud 90.A clevis 94 engages a slot in an arm 95 of the latch and is connected bylinks 97 and 98 to key levers 99 and 100, as shown. Upon actuation ofeither one of these keylevers, the latch 91 is rocked to release the cam85 so that the arm 87 forces it into engagement with the power roll. Asthe cam is rotated by the power roll, the cam lever 81 is caused torotate about a pivot point 102 in a clockwisedirection.

Arranged below the cam lever adjacent its rear end is a member 104pivotally mounted in a bracket 105 and having an arm 106 engageable withthe lower end of the latch 70 for holding the latter free of the portion68 on the bellcrank 63. Formed in the member 104 is an L-shaped slot 197receiving a pin 108 of a clevis 109 which is connected by a link 110 toan arm 111 integral with the key lever 99. The link 110 is normally heldby a spring 112 in such a position that the pin 108 lies in the verticalportion of the L-shaped slot 107, as shown in Fig. 3. The member 104 isurged upwardly by a spring 114 against an abutment 115 to position thearm 186 for engagement with the lower end of the latch 70.

As the key lever 99 is depressed, the link 110 is first actuated toswing the member 104 so that the arm 106 is removed from the latch 70.This latch is then moved by the spring 82 to a position for engaging theportion 68 of the bellcrank 63. Depression of the key lever 99 alsoactuates the link 97 to rook the latch 91 out of the path of the stud 90on the cam 85. The spring arm 87 then rocks the cam against the powerroll which drives the cam to effect a rocking of the cam lever 81 in aclockwise direction about its pivot 102. As the cam lever rocks, thelatch 70 is pulled downwardly and causes the bellcrank 63 to rock in aclockwise direction. Since the bridge portion 67 on the bellcrank 63overlies the bellcrank 55, the latter bellcrank is also caused to rockin a clockwise direction. These bellcranks are rocked to a positionwhere the latch 72 engages the upper edge of the arm portion 66 on thebellcrank 63 and causes both bellcranks to be held in their rockedpositions. The rocking of the bellcrank 63 causes the arm 58 to beactuated for engaging the roller 44 with the clutch spring 41 andcausing the gear 38 to be driven for rotating the shaft 12. Rocking ofthe bellcrank 55 causes the pawl 49 to be disengaged from the ratchetwheel 48.

During the swinging of the cam lever 81 about its pivot, a projection116 on the lower end of the latch 70 is engaged with the link 110 toforce the latter downwardly until the clevis pin 108 is moved into thehorizontal portion of the L-shaped slot 107. This permits the member 104to be swung upwardly by the spring 114 until the arm portion 106 engagesa surface 117 on the lower end of the latch 70. At the forward side ofthe latch 70 is a member 118 engageable by a cam surface 119 on thelatch for forcing the latter away from the portion 68 of the bellcrank63 when the arm portion 66 is in position to be engaged by the latch 72.As the latch 70 is cammed away from the portion 68, the arm 106 of themember 104 moves from the surface 117 to a. position in back of thelatch 70 for holding the latter in its released position.

Formed on the rear end of the cam lever is a cam surface 120 which isengageable with a roller 122 carried by a bellcrank 123 for rocking thelatter about a pivot point 124. A link 125 is connected at one end tothe bellcrank 123 and is connected at its other end to another bellcrank126 which has mounted on it a dog 127 engageable with a ratchet wheel128 fixed to the platen 3. On each rocking motion of the cam lever 81,the bellcrank 123 is operated to actuate the dog 127 for indexing theplaten.

-It will be noted that a depression of the key lever 99 results in areleasing of the cam 85 to engage the power roll for rocking the camlever, and the member 104 is also actuated to release the latch 70 sothat it can effect an engagement of the clutch spring 41 to drive theshaft 12 and also disengage the pawl 49 from the ratchet wheel '48. Adepression of the key lever 100, however, results only in a release ofthe cam 85 to engage the power roll for rocking the cam lever 81. Duringthis time, the member 104 remains in the position shown to hold thelatch 76 out of engagement with the portion 68 on the bellcrank 63. Therocking of the cam lever results in an indexing of the platen but, sincethe bellcrank 63 is not actuated, the cairiage 'r'etiiainsstationary..As mentioned above, a depression of. the key lever 99 results in arelease ofthe pawl 49 from the ratchet wheel 48 and an operation ofthe'clutch spring 41 to effect a driving of the shaft 12in a clockwisedirection for moving the carriage Z to the left. Fixed to the carriageis a lproiecting member 130 which is engageable with a stop 131adjustably: mounted on a rack I32 extending trans -verseIy of thetypewriter parallel to the sh'aft14. The rack is slidably supported atits left end, as shown in Fig. 1, by a frame portion 134, and a spring135 acts between. the frame and the rack for urging the latter to Itheright. Similar supporting means is provided for the :right hand end ofthe rack. Formed upon the rack at tits right end is a portion 136extending beyond the frame :support and carrying a pm 137 engaging abellcrank 138 whichis connected by a link 139, as shown in Fig. 3, tothe member 75. The pull on the member 75 by the :spring 79 operatesthrough the link 139 to hold the bellcrank 138 against the pin 137.

The stop 131 is positioned on the rack 132 so that :it is first engagedby the member 130 when the carriage .2 is in.a position for typing atthe beginning of a line. .As the carriage is driven to the left, themember 130 engages the stop 131 and causes the rack 132 to move :againstthe action of the spring 135. This movement of the rack causes thebellcrank 138 to swing about its pivot 1-40 and rock the member 75 in acounter clockwise direction in Fig. 3. During the first part of therocking :motion by member 75, the latch 71 is permitted to move ninderthe action of the spring 74 to a position for latching the arm portion65 of the bellcrank 55. The finger 77 on the member 75 then engages thelatch 72 and moves the latter out of contact with the arm portion 66 ofthe bellcrank 63. As soon as the bellcrank 63 is nnlatched, the roller44 is moved out of engagement with the clutch spring 41 by a swinging ofthe arm 58 under the action of the spring 60. This results in release ofthe drive connections to the carriage but the latter may continue tomove to the left under its inertia against the action of the spring 47tending to rotate the shaft 12 in a counter clockwise direction. Thespring 135 acting on the rack 132 will also operate to oppose movementof the carriage after the drive clutch has been disengaged. When theinertia of the carriage has been overcome by the springs 47 and 135, thecarriage is moved to the right and the rack 132 moves with it. Movementof the rack permits the member 75 to rock clockwise about its pivotunder the action of the spring 79. As the carriage approaches theposition for typing at the beginning of a line, the eccentric 76 on themember 75 moves the latch 71 out of engagement with the arm portion 65of the bellcrank 55. This results in an operation of the pawl 49 by thespring 51 to engage the ratchet wheel 48 when the carriage reaches thebeginning of the line and causes it to be held against further movementby the spring 47.

Movement of the carriage to the right from the beginning of a line oftype takes place under the action of the spring 47 as the pawl 49 isoperated upon actuation of type keys, a space bar, or a tabulation key,not shown. As shown and described in the Palmer application referred toabove, a shaft 133, Fig. 4, is caused to rotate 180 upon each actuationof a type key. Mounted upon the shaft 133 is a cam 142 which actuates abellcrank 143 once upon each turning of the shaft through 180. A link144 connects the bell crank 143 to a bellcra-nk 145 which actuates thepawl 49 to permit a rotation of the wheel 48 one tooth space foreffecting escapement of the carriage. Tabulation may be obtained byholding the pawl free of the ratchet wheel 48 through any suitablemeans, not shown, until the carriage engages a tabulation stop.

When the carriage is released for movement to the right a substantialdistance under the action of the spring 47, the carriage speed maybecome. eiicessive unless som regulating means is provided. To controlthe. speed. of the carriage, there is provided a bevel gear 147 freelymounted on the shaft. 22 and meshing with the. gear 46* As the spring 47rotates the shaft 12. tov move the Carriage to the right, the gear 46drives. the gear'1 47 in the same direction as the shaft 22 rotates.Fixed to the. shaft 22, as shown in Fig. 2', is a sleeve member 148.Coiled about the member 148-and'. a hub1l4 9' of the gear 147 is aspring 150. This springiis. coiled'abo'ut the member 148 and the hub 149in the same direction as the shaft rotation looking fromleft to rightand has frictional engagement therewith. It will be seen that. a-IQ-tation of the gear 147 at a speed below that of the shaft results in anexpanding of the spring. 150 so that. it. does not affect the turning ofthe gear. If thefg ear 147 tends to rotate, however, atv a speed greaterthan that of the shaft, the spring 150 grips the member 148 and the hub149 and places such a load on the gear 147 that it can be driven only atthe speed of the shaft.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intentiontherefore, to be limited only as indicated by the scope of the followingclaims.

What is claimed is:

1. A mechanism for moving a typewriter carriage from any typing positionin a line to a position for typing at the beginning of the linecomprising, in combination, power means, meansadapted to be actuated bysaid power means for moving said carriage toward a position at whichtyping may take place at the beginning of the line, a clutch mechanismfor controlling the connection of said power actuated means to saidpower means, means for yieldingly urging said carriage in a directionopposite to the movement by said power actuated means, means normallyholding said carriage against movement by said yielding means, meansincluding a pair of members movable against the action of yieldablemeans to a control position, one member operating on movement to suchposition for engaging said clutch mechanism and the second memberoperating to release said holding means, manually controlled power meansfor moving said members to said control position, a first latch operableto hold said pair of members in said control position when movedthereto, a second latch engageable with said second member when in saidcontrol position, means operating on movement of said carriage to saidposition at the beginning of the line for releasing said first latchfrom said pair of members and engaging said second latch with saidsecond member, said carriage moving by inertia beyond said position atthe beginning of the line against the action of said yielding means, andmeans operating on return of said carriage to said position fordisengaging said second latch from said second member.

2. The mechanism of claim 1 in which said manually controlled powermeans includes. a cam lever, a continuously driven power roll, a cam onsaid lever engageable with said power roll, a key lever operablemanually for effecting engagement of said cam with said power roll, alatch pivoted on said cam lever and engageable with said pair ofmembers, means yieldingly urging said latch toward said pair of members,and means operating upon predetermined movement of said cam lever formoving said latch out of engagement with said pair of members.

3. A mechanism for moving a typewriter carriage from any typing positionin a line to a position for typing at the beginning of another linecomprising, in combination, power means, means adapted to be actuated bysaid power means for moving said carriage toward the beginning of aline, a clutch mechanism for controlling the connection of said poweractuated means to said power means, means yieldingly urging saidcarriage in the opposite direction, a ratchet and pawl normally holdingsaid carriage against movement by said yielding means, means including apair of bellcranks movable to a control position, one operating to applysaid clutch and the second operating to release said holding means, afirst latch operable to hold said bellcranks in their control position,a second latch operable to hold said second bellcrank in its controlposition, a cam lever, a third latch pivoted on said cam lever andengageable with said bellcranks for moving them to said controlposition, a

cam mounted on said cam lever, a continuously rotating 15 power roll,means including a key lever operable to engage said cam with said powerroll for effecting a rocking of'said cam lever, indexing means operableby said cam lever, means operating on movement of said carriage to saidtyping position at the beginning of a line to disengage said first latchfrom said bellcranks and to engage said second latch with said secondbellcrank, and means operating on return of said carriage to saidposition for disengaging said second latch from said second bellcrank.

4. The mechanism of claim 3 including a member engageable with saidthird latch for holding it free from said bellcranks, and means operableby said key lever for disengaging said holding member from said thirdlatch.

References Cited in the file of this patent UNITED STATES PATENTS2,258,116 Khalil Oct. 7, 1941 2,797,789 Yaeger July 2, 1957 2,831,558Toggenburger Apr. 22, 1958.

